Devices such as mobile devices perform various functions. For example, such devices may initiate and receive telephonic communications, display image content such as documents, e-mails, and pictures on a screen, and download information and applications from the Internet. In some examples, a device may be configured to accept a voice command and perform a function in response to the voice command. For example, the device may be configured to allow a user to speak the voice command “call Bob,” and, in response to the voice command, initiate a telephonic communication link by dialing a telephone number of a device associated with the name “Bob.”